Apparently the machete weilding undercarriages of robotic lawnmowers are temptation enough to send these backyard domestic servants into a murderous rampage when ordered to mow a hill of lawn considered too steep by the little can-heads. A Danish man found this out the hard way. His Dvorak Spider 01 robot lawnmower revolted upon the command to mow a slope, and tumbled on the man's head.